The invention relates to a folic acid modified chitosan micro-capsule with reducing responsiveness and a preparation method thereof. The capsule wall is modified by folic acid and provided with a disulfide bond structure with reducing responsiveness, a chitosan crosslinking film modified by folic acid and compounds with sulfydryl or biomolecules is adopted as the capsule wall, and the oil phase loaded with hydrophobic drugs is adopted as a core material. Firstly, chitosan is modified by folic acid and the compounds with sulfydryl or the biomolecules, ultrasonic radiation is conducted on the oil phase loaded with the hydrophobic drugs and a chitosan water solution modified by the compounds with sulfydryl or the biomolecules, and the chitosan drug-loaded micro-capsule with the capsule wall provided with folic acid and the disulfide bond structure is obtained. The preparation method is rapid, easy and convenient, efficient, environmentally friendly and wide in material source, the product is pure and free of toxins, the drug loading capacity is large, the micro-capsule can be widely applied to covering the hydrophobic drugs, targeted conveyance of drugs is achieved through the targeting of folic acid, controllable release of the drugs is achieved through the reducing responsiveness of disulfide bonds, and good application prospects are achieved.